Washington Revised Code Title 62A. Uniform Commercial Code § 62A.2-607. Effect of acceptance; notice of breach; burden of establishing breach after acceptance; notice of claim or litigation to person answerable over

(a) The buyer must within a reasonable time after he or she discovers or should have discovered any breach notify the seller of breach or be barred from any remedy; and

(b) If the claim is one for infringement or the like (RCW 62A.2-312(3)) and the buyer is sued as a result of such a breach, he or she must so notify the seller within a reasonable time after he or she receives notice of the litigation or be barred from any remedy over for liability established by the litigation.

(a) He or she may give his or her seller written notice of the litigation. If the notice states that the seller may come in and defend and that if the seller does not do so he or she will be bound in any action against him or her by his or her buyer by any determination of fact common to the two litigations, then unless the seller after seasonable receipt of the notice does come in and defend he or she is so bound.

(b) If the claim is one for infringement or the like (RCW 62A.2-312(3)), the original seller may demand in writing that his or her buyer turn over to him or her control of the litigation including settlement or else be barred from any remedy over and if he or she also agrees to bear all expense and to satisfy any adverse judgment, then unless the buyer after seasonable receipt of the demand does turn over control the buyer is so barred.